PDA

View Full Version : Blow In Or Blow Out?



GrubMe
03-05-2004, 07:40 AM
Hello...

I have 3 case fans in my computer...
I have it blowing in...
The inside of my computer is fairly cold...
My room is not hot... not warm but fairly even...
Is that good or bad?

delphin460
03-05-2004, 09:23 AM
hmmm, although its might not sound much, the idea is to remove the heat from within you comp box, to effectivly do this flow through is important

it no good trying to pump shit loads of air in if it all cant get out.

best bet is to try and have an air intake = air exhaust

if you have 3 case fans installed then all the holes to let the air out will be blocked

try reversing at least 1 of the fans if not 2, so airflow will increase over the board and out of the case

its pretty technical but if you have all your fans blowing inward, and no way to get that air out you will create a positive pressure inside the case, and this will infact increase the internal temp, same will happen if you have all the fans blowing

this theory comes from speaker technology, where high powered subs get fried cause the airflow is too low or is unable to escape.

room temp ( ambient temp ) will effect the comp temp no matter what you do as the air has to come from somewhere and go somewhere

clocker
03-05-2004, 12:39 PM
ts pretty technical but if you have all your fans blowing inward, and no way to get that air out you will create a positive pressure inside the case, and this will infact increase the internal temp, same will happen if you have all the fans blowing

this theory comes from speaker technology, where high powered subs get fried cause the airflow is too low or is unable to escape.
It's a nice theory, but translates poorly to computers.
I have yet to see a computer case that wasn't riddled with holes, vents, loose joints, etc.
The concept of "establishing pressure" ( be it positive or negative) in the average PC enclosure is laughable, IMO.
Furthermore, using the typical 80mm case fan, "airflow" through a mid-tower sized case doesn't occur either. Simply put, a axial 80mm fan just doesn't expel a stream of moving air coherent enough to be described as a continuous "flow".
All the pretty pictures of case interiors with arrows depicting the flow of air ( Apple seems fond of this image) are figments of the marketing department's imagination.

Grub, ignore for a moment the theory of case fan placement and concentrate instead on your temps.
Which you failed to mention.

Chewie
03-05-2004, 04:17 PM
The only consideration I heed is that heat rises so the rear case and PSU fans blow out, while my case front blows in.
I doubt it makes a lot of difference (my temps aren't low) but at least it's following the laws of physics to a degree. :)

clocker
03-05-2004, 04:37 PM
Originally posted by Chewie UK@5 March 2004 - 08:17

I doubt it makes a lot of difference (my temps aren't low) but at least it's following the laws of physics to a degree. :)
How far are you willing to follow the laws of physics?
Have you tried any other configuration?
You really have nothing to lose, as you've already admitted that your temps "aren't low".

_John_Lennon_
03-05-2004, 07:05 PM
Very true clocker, 80MM fans that people use in their cases just dont give a nice air flow. They can bring in cooler air, and expel hot air, but they dont have enough CFM to create a nice breeze in the case.

Im my previous case, which was a mid tower, I was able to put one of my 120MM panflos on the 5.25 rack, and another in the middle way back of the bottom middle of the case, and I was able to acheive the constant air flow.

Chewie
03-05-2004, 10:12 PM
Originally posted by clocker+5 March 2004 - 16:37--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (clocker @ 5 March 2004 - 16:37)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Chewie UK@5 March 2004 - 08:17

I doubt it makes a lot of difference (my temps aren&#39;t low) but at least it&#39;s following the laws of physics to a degree. :)
How far are you willing to follow the laws of physics?
Have you tried any other configuration?
You really have nothing to lose, as you&#39;ve already admitted that your temps "aren&#39;t low". [/b][/quote]
Not very far, mate. :D
I really don&#39;t see the point of spending hours/days/weeks fiddling around with modding to allow overclocking because you just end up spending less time actually using it.
Some may consider my Thoroughbred to be too hot at ~50C and I should look into getting it down but, really... it&#39;s well below AMD&#39;s recommended max temp of 90C and the amount of difference my high temp is gonna make to it&#39;s lifespan isn&#39;t even worth the effort of working it out&#33;

It would&#39;ve been nice if manufacturers had thought a little more in designing board formats; why put the CPU at the top of a tower case if heat is an issue? Similarly, why are GPUs situated on the underside of gfx cards when they&#39;re in a tower case? Shit, people spend weeks poring over real or perceived heat issues and these simple design features could&#39;ve given them some sleep&#33; :)

lynx
03-05-2004, 10:34 PM
Originally posted by Chewie UK+5 March 2004 - 21:12--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Chewie UK @ 5 March 2004 - 21:12)</td></tr><tr><td id='QUOTE'>
Originally posted by clocker@5 March 2004 - 16:37
<!--QuoteBegin-Chewie UK@5 March 2004 - 08:17

I doubt it makes a lot of difference (my temps aren&#39;t low) but at least it&#39;s following the laws of physics to a degree. :)
How far are you willing to follow the laws of physics?
Have you tried any other configuration?
You really have nothing to lose, as you&#39;ve already admitted that your temps "aren&#39;t low".
Not very far, mate. :D
I really don&#39;t see the point of spending hours/days/weeks fiddling around with modding to allow overclocking because you just end up spending less time actually using it.
Some may consider my Thoroughbred to be too hot at ~50C and I should look into getting it down but, really... it&#39;s well below AMD&#39;s recommended max temp of 90C and the amount of difference my high temp is gonna make to it&#39;s lifespan isn&#39;t even worth the effort of working it out&#33;

It would&#39;ve been nice if manufacturers had thought a little more in designing board formats; why put the CPU at the top of a tower case if heat is an issue? Similarly, why are GPUs situated on the underside of gfx cards when they&#39;re in a tower case? Shit, people spend weeks poring over real or perceived heat issues and these simple design features could&#39;ve given them some sleep&#33; :) [/b][/quote]
I agree with what you are saying, particularly about case and component design, but there&#39;s a point you&#39;ve overlooked.

Amd&#39;s max temp is the temp above which you are likely to do permanent damage to the chip. They are NOT guaranteeing that the chip will be stable if you operate at temps close to the maximum.

I often find that instability occurs (especially hangups) when Amd chips approach 60C, and often much lower if the chips are overclocked. But that&#39;s just a direct consequence of the physics involved, which is why it is important to get lower temps than normal if you are overclocking.

clocker
03-05-2004, 11:52 PM
Chewie,
Many of your concerns will be addressed with the new BTX form factor...coming soon to a theater near you.

It looks to be a little better although they still insist on describing the "airflow" that will cool the processor then continue on to the memory, etc.
Bollocks.

GrubMe
03-06-2004, 01:57 AM
So i should put 2 fans blowing in and 1 blowing out?

clocker
03-06-2004, 02:00 AM
You should try every possible combination you can think of, take note of temps and then decide for yourself.
You have nothing to lose but time and may learn something about the peculiarities of your case in the process.

kaiweiler
03-06-2004, 02:01 AM
Originally posted by GrubMe@5 March 2004 - 21:57
So i should put 2 fans blowing in and 1 blowing out?
Give it a try one way, chack your temps, if your not satisfied, try changing it around untill you get it the way you like it.
Just make sure you place your fans blowing into places that actually need more airflow, and don&#39;t just make em blow into a corner or some useless place that doesnt need mroe airflow.
Just blow onto all the major parts ie. HD, CPU, RAM, PSU, ETC

GrubMe
03-06-2004, 05:38 AM
How can you check your Temp?
Install a program?
In your BIOS?
Windows XP?

Well I blowed 2 in, 1 out... so cool now...
But how can you check your temperature?

clocker
03-06-2004, 05:41 AM
MotherboardMonitor5 or SpeedFan will work.
Google is your friend.

GrubMe
03-06-2004, 05:43 AM
thank you...
Is this uninstallable?
No spyware etc...
wont damage my computer? ^^

GrubMe
03-06-2004, 05:45 AM
Hmm kind of confusing ... well my specs are there if someone can find the appropraite hardware and link to me thank you.

GrubMe
03-06-2004, 06:00 AM
my temp is like 23

How can i configure my case fan?
there are like temp1,2,3?
Which one is the case fan?

delphin460
03-06-2004, 06:50 AM
cpu is usualy 1 , system fans are 2 and 3

GrubMe
03-06-2004, 06:53 AM
is there any programs... that can control your case fans? instead of your spu fans etc? cause my case fans goes really fast that it makes noise.

what you mean system fans? case fans?

tesco
03-07-2004, 01:48 AM
Originally posted by GrubMe@6 March 2004 - 01:53
is there any programs... that can control your case fans? instead of your spu fans etc? cause my case fans goes really fast that it makes noise.

what you mean system fans? case fans?
are your case fans connected using molex connectors or are they plugged into the motherboard? the motherboard fans can be controlled but molex ones cant.

If they are molex you can either build a speed controller or buy one from a computer shop.